If I open Lightroom CC on my Eizo FlexScan EV3895 monitor (3840x1600), masks briefly show in the mask list but then disappear completely. The same happens when I create a new mask. It quickly flashes in the mask list and then disappears (see Pic 2).
However, if I open Ligthroom on my laptop screen first, everything is fine (see Pic 1). Masks still show if I move Lightroom window from the laptop screen to the bigger Eizo screen. This is a workaround, but really annoying.
I have tried to resize Lightroom window to a smaller size and reopen it to mimic the window size of the laptop screen on the big screen. This doesn't make any difference. So, masks only show up, if LR is first opened on the laptop screen.
Thanks for reaching out. We are sorry for the trouble with Lightroom. I'd love to help you figure this out.
Could you please share the specific version of Lightroom you are working on? Have you set the external display as primary in Windows settings? Do you experience this behavior with only Lightroom? Do any other applications also behave similarly?
Have you tried any troubleshooting steps?
Go to the following location and set the scaling options in the explorer to find out what works best for your multi-monitor setup.
C:\Program Files\Adobe\Adobe Lightroom CC
Right-click on Lightroom.exe > Properties > Compatibility > Change Settings for all users > Change High DPI Settings > High DPI Scaling Overide > Check the option 'Override High DPI scaling behavior.' > Scaling Performed by > Test & choose from the following options one by one > Application , System & System (Enhanced)
Apply each of these settings as a test.
If this does not work, please share a video recording of this behavior.